Patent GB-616516-A (GB)
Title: Improvements in and relating to control systems for power driven movable objects
IPC: G05D3/14
Filed: 1942-01-08
Abstract: 616,516. Electric control systems. TUSTIN, A., MORRIS, D. C. O., BRAITHWAITE, R. C., SOMERVILLE, T. B., SIMMONS, J. D., and METROPOLITAN - VICKERS ELECTRICAL CO., Ltd. Jan. 8, 1942, Nos. 332, 1104 and 16486. [Class 40 (i)] [Also in Groups XXXV and XXXVII] Relates to a system for orientating an object, e.g., a gun mounting relatively to a moving supporting structure, and consists in producing a signal dependent on the sum of the angular velocities of the mounting with respect to the structure and of the structure with respect to space by means of a gyroscope, and applying this signal and the signal controlling the mounting to an amplifier whose output is applied to maintain the desired rotation of the mounting when the difference between the actual and desired rotation is small. In the arrangement shown in Fig. 1, the gun mounting is trained by D.C. motor 1, the armature of which is supplied by metadyne 2 having a centre-tapped variator winding 6 controlled by a pair of vibrating regulators (contacts 20, 22 arid 21, 23) having vibration maintaining windings 37, 38, differential windings 47 48, governed by a manually controlled potentiometer 8 and further differential windings 52-55 governed by a further vibrating regulator under the control of gyroscope 60 carried by the moving structure. The differential windings 41, 42, vary the make-and-break ratios of the respective vibrators in opposite senses so that the speed and direction of rotation of motor 1 is dependent on the position of the manual control, and the windings 52-55 further modify the ratios in opposite senses so that the motor has a speed component depending on the angular velocity of the structure in space in a direction opposite to the angular movement of the structure. Additional windings 47, 48 connected to the motor armature circuit serve to stabilize the speed of the drive corresponding to any particular value of control. A choke 51 in series with windings 47, 48 or a phase advancing circuit associated with windings 41, 42 introduces a component dependent on the speed of the manual control as described in Specifications 577,315, [Group XXXVII] and 609,304 respectively, to compensate for lag or inertia of the motive equipment. The choke 51 also introduces a component dependent on the rate of change of angular velocity of the movable structure but this may be separately effected by phase advancing the output of the gyro-regulator. Alternatively, the regulator may be provided with additional coils 73, 74 in series with a choke 75 and connected-to the fixed contacts 22<SP>1</SP>, 231. Instead of using armature voltage to control the effect of windings 47, 48, a tachometer generator driven by the motor may be used for this purpose. Modifications. In Fig. 4 (not shown) the control by windings 47, 48 in accordance with the speed of the motor is replaced by a further gyro-regulator control in which the gyroscope is mounted on the gun mounting so that it is sensitive to rotation about an axis parallel to the axis of rotation of the gun mounting and therefore provides a control in accordance with the angular speed of the gun mounting. The vibrator may have auxiliary phase advancing windings as described for the other gyroregulator, but in the present case it also has windings controlled by the manual potentiometer replacing the windings 41, 42 on the main regulator. These last mentioned windings are arranged to oppose the windings controlled by the gun gyro so that the motor has a speed component corresponding to the speed represented by the position of the manual control since the output of the gun gyro-regulator is fed to windings on the main regulator. The main regulator also has additional windings energized in accordance with the movement of a frictional device carried by the armature shaft to provide a component compensating the effects of friction in the motive equipment. If the inertia of the motive equipment is low, the further gyro-regulator on the gun mounting may be relied on to effect operation of the gun at a speed corresponding to the position of the manual control (Fig. 7, not shown). The structure gyro is omitted. In the modification shown in Figs. 5 and 6, the frame of the main stabilizing gyro 60, instead of being fixed on the supporting structure, is pivotally mounted about the axis CD of the angular movement of the structure it is required to sense, and an auxiliary motor 133 tends to maintain the frame fixed in space. When angular movement of the structure occurs, the gyro frame tends to follow owing to frictional and inertia effects but the precession operating on the vibrating regulator 17<SP>1</SP> provides an output to the field winding of auxiliary motor 139 which restores the frame. The output is also fed to windings 140, 141 on the main regulator which replace the windings 52-55, Fig. 1, and also auxiliary windings described with reference to Fig. 4, and providing the friction component, since frictional components enter into the output from the gyro regulator, Fig. 6, and may be proportioned to compensate friction in the main motive equipment. Phase advance may be introduced by windings 136, 137 as described in Specification 609,304. Fig. 6 may be modified for directly replacing the control gyro in Fig. 1, by energizing the motor field 138 from the D.C. supply 4, 5 and connecting the armature across contacts 22, 23, directly or through an amplifier, the coils 52-55 being then connected across the armature with a series resistance if an acceleration component is required. Stabilization against cross-roll, Fig. 8. An additional gyro-regulator 152 sensitive to crossroll is mounted on the movable structure and supplies additional windings 150, 151 on the main regulator 7, Fig. 1, or on the further gyro-regulator referred to in the description of the modifications, Figs. 4 and 7 (not shown). The Specification shows that for training movements, connection is required proportional to the tangent of the angle of elevation and for this purpose the output is taken across potentiometer 157 controlled by elevational movement, the control or grading of the potentiometer providing a tangent law. Specifications 577,312, 579,050, [both in Group XXXVII], 616,602, and 616,603, [Group XXXVII], also are referred to.